Exfiltration Over Alternative Protocol: Exfiltration Over Symmetric Encrypted Non-C2 Protocol
- ID
- T1048.001
- Tactics
- TA0010 Exfiltration
- Sub-technique of
- T1048 Exfiltration Over Alternative Protocol
- Platforms
- Linux, macOS, Windows, ESXi
- Data sources
- Network Connection Creation, Process Creation, Network Traffic Flow, Network Traffic Content, Command Execution
- Source
- attack.mitre.org
- MITRE last modified
- 3 Sep 2026
Adversaries may steal data by exfiltrating it over a symmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server.
Symmetric encryption algorithms are those that use shared or the same keys/secrets on each end of the channel. This requires an exchange or pre-arranged agreement/possession of the value used to encrypt and decrypt data.[2]
Network protocols that use asymmetric encryption often utilize symmetric encryption once keys are exchanged, but adversaries may opt to manually share keys and implement symmetric cryptographic algorithms (ex: RC4, AES) vice using mechanisms that are baked into a protocol. This may result in multiple layers of encryption (in protocols that are natively encrypted such as HTTPS) or encryption in protocols that not typically encrypted (such as HTTP or FTP).
Detection
- DET0503 Behavioral Detection Strategy for Exfiltration Over Symmetric Encrypted Non-C2 Protocol
Data components: Network Connection Creation, Process Creation, Network Traffic Flow, Network Traffic Content, Command Execution
Mitigations (3)
- M1030 Network Segmentation
Follow best practices for network firewall configurations to allow only necessary ports and traffic to enter and exit the network.[1]
- M1031 Network Intrusion Prevention
Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary command and control infrastructure and malware can be used to mitigate activity at the network level.
- M1037 Filter Network Traffic
Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
References
- TechNet Firewall Design
- Exfiltration Over Symmetric Encrypted Non-C2 Protocol